TY - JOUR
T1 - Ion Coordination and Transport in Magnesium Polymer Electrolytes Based on Polyester-co-Polycarbonate
AU - Park, Bumjun
AU - Andersson, Rassmus
AU - Pate, Sarah G.
AU - Liu, Jiacheng
AU - O’Brien, Casey P.
AU - Hernández, Guiomar
AU - Mindemark, Jonas
AU - Schaefer, Jennifer L.
N1 - Funding Information:
We thank Prof. Ruilan Guo for DSC instrumentation and Tatyana Orlova and the University of Notre Dame Integrated Imaging Facilities for SEM. JM, GH, and RA acknowledge the financial support from STandUP for Energy. JLS, BP, and JL acknowledge the partial financial support from NSF CBET-1706370. JLS, BP, JL, CPO, and SGP acknowledge the additional financial support from the University of Notre Dame.
Publisher Copyright:
Copyright © 2021 Bumjun Park et al.
PY - 2021
Y1 - 2021
N2 - Magnesium-ion-conducting solid polymer electrolytes have been studied for rechargeable Mg metal batteries, one of the beyond-Li-ion systems. In this paper, magnesium polymer electrolytes with magnesium bis(trifluoromethane)sulfonimide (Mg(TFSI)2) salt in poly(ε-caprolactone-co-trimethylene carbonate) (PCL-PTMC) were investigated and compared with the poly(ethylene oxide) (PEO) analogs. Both thermal properties and vibrational spectroscopy indicated that the total ion conduction in the PEO electrolytes was dominated by the anion conduction due to strong polymer coordination with fully dissociated Mg2+. On the other hand, in PCL-PTMC electrolytes, there is relatively weaker polymer–cation coordination and increased anion–cation coordination. Sporadic Mg- and F-rich particles were observed on the Cu electrodes after polarization tests in Cu|Mg cells with PCL-PTMC electrolyte, suggesting that Mg was conducted in the ion complex form (MgxTFSIy) to the copper working electrode to be reduced which resulted in anion decomposition. However, the Mg metal deposition/stripping was not favorable with either Mg(TFSI)2 in PCL-PTMC or Mg(TFSI)2 in PEO, which inhibited quantitative analysis of magnesium conduction. A remaining challenge is thus to accurately assess transport numbers in these systems.
AB - Magnesium-ion-conducting solid polymer electrolytes have been studied for rechargeable Mg metal batteries, one of the beyond-Li-ion systems. In this paper, magnesium polymer electrolytes with magnesium bis(trifluoromethane)sulfonimide (Mg(TFSI)2) salt in poly(ε-caprolactone-co-trimethylene carbonate) (PCL-PTMC) were investigated and compared with the poly(ethylene oxide) (PEO) analogs. Both thermal properties and vibrational spectroscopy indicated that the total ion conduction in the PEO electrolytes was dominated by the anion conduction due to strong polymer coordination with fully dissociated Mg2+. On the other hand, in PCL-PTMC electrolytes, there is relatively weaker polymer–cation coordination and increased anion–cation coordination. Sporadic Mg- and F-rich particles were observed on the Cu electrodes after polarization tests in Cu|Mg cells with PCL-PTMC electrolyte, suggesting that Mg was conducted in the ion complex form (MgxTFSIy) to the copper working electrode to be reduced which resulted in anion decomposition. However, the Mg metal deposition/stripping was not favorable with either Mg(TFSI)2 in PCL-PTMC or Mg(TFSI)2 in PEO, which inhibited quantitative analysis of magnesium conduction. A remaining challenge is thus to accurately assess transport numbers in these systems.
UR - http://www.scopus.com/inward/record.url?scp=85127515969&partnerID=8YFLogxK
U2 - 10.34133/2021/9895403
DO - 10.34133/2021/9895403
M3 - Article
AN - SCOPUS:85127515969
SN - 2692-7640
VL - 2021
JO - Energy Material Advances
JF - Energy Material Advances
M1 - 9895403
ER -